Index: head/sys/netinet/tcp_hostcache.c =================================================================== --- head/sys/netinet/tcp_hostcache.c (revision 358022) +++ head/sys/netinet/tcp_hostcache.c (revision 358023) @@ -1,748 +1,750 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 2002 Andre Oppermann, Internet Business Solutions AG * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * The tcp_hostcache moves the tcp-specific cached metrics from the routing * table to a dedicated structure indexed by the remote IP address. It keeps * information on the measured TCP parameters of past TCP sessions to allow * better initial start values to be used with later connections to/from the * same source. Depending on the network parameters (delay, max MTU, * congestion window) between local and remote sites, this can lead to * significant speed-ups for new TCP connections after the first one. * * Due to the tcp_hostcache, all TCP-specific metrics information in the * routing table have been removed. The inpcb no longer keeps a pointer to * the routing entry, and protocol-initiated route cloning has been removed * as well. With these changes, the routing table has gone back to being * more lightwight and only carries information related to packet forwarding. * * tcp_hostcache is designed for multiple concurrent access in SMP * environments and high contention. All bucket rows have their own lock and * thus multiple lookups and modifies can be done at the same time as long as * they are in different bucket rows. If a request for insertion of a new * record can't be satisfied, it simply returns an empty structure. Nobody * and nothing outside of tcp_hostcache.c will ever point directly to any * entry in the tcp_hostcache. All communication is done in an * object-oriented way and only functions of tcp_hostcache will manipulate * hostcache entries. Otherwise, we are unable to achieve good behaviour in * concurrent access situations. Since tcp_hostcache is only caching * information, there are no fatal consequences if we either can't satisfy * any particular request or have to drop/overwrite an existing entry because * of bucket limit memory constrains. */ /* * Many thanks to jlemon for basic structure of tcp_syncache which is being * followed here. */ #include __FBSDID("$FreeBSD$"); #include "opt_inet6.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #include #include #endif #include #include #include #ifdef INET6 #include #endif #include /* Arbitrary values */ #define TCP_HOSTCACHE_HASHSIZE 512 #define TCP_HOSTCACHE_BUCKETLIMIT 30 #define TCP_HOSTCACHE_EXPIRE 60*60 /* one hour */ #define TCP_HOSTCACHE_PRUNE 5*60 /* every 5 minutes */ VNET_DEFINE_STATIC(struct tcp_hostcache, tcp_hostcache); #define V_tcp_hostcache VNET(tcp_hostcache) VNET_DEFINE_STATIC(struct callout, tcp_hc_callout); #define V_tcp_hc_callout VNET(tcp_hc_callout) static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *); static struct hc_metrics *tcp_hc_insert(struct in_conninfo *); static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS); static int sysctl_tcp_hc_purgenow(SYSCTL_HANDLER_ARGS); static void tcp_hc_purge_internal(int); static void tcp_hc_purge(void *); static SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, CTLFLAG_RW, 0, "TCP Host cache"); VNET_DEFINE(int, tcp_use_hostcache) = 1; #define V_tcp_use_hostcache VNET(tcp_use_hostcache) SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, enable, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_use_hostcache), 0, "Enable the TCP hostcache"); SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, cachelimit, CTLFLAG_VNET | CTLFLAG_RDTUN, &VNET_NAME(tcp_hostcache.cache_limit), 0, "Overall entry limit for hostcache"); SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, hashsize, CTLFLAG_VNET | CTLFLAG_RDTUN, &VNET_NAME(tcp_hostcache.hashsize), 0, "Size of TCP hostcache hashtable"); SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, bucketlimit, CTLFLAG_VNET | CTLFLAG_RDTUN, &VNET_NAME(tcp_hostcache.bucket_limit), 0, "Per-bucket hash limit for hostcache"); SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, count, CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(tcp_hostcache.cache_count), 0, "Current number of entries in hostcache"); SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, expire, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_hostcache.expire), 0, "Expire time of TCP hostcache entries"); SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, prune, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_hostcache.prune), 0, "Time between purge runs"); SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, purge, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_hostcache.purgeall), 0, "Expire all entires on next purge run"); SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, list, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP, 0, 0, sysctl_tcp_hc_list, "A", "List of all hostcache entries"); SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, purgenow, CTLTYPE_INT | CTLFLAG_RW, NULL, 0, sysctl_tcp_hc_purgenow, "I", "Immediately purge all entries"); static MALLOC_DEFINE(M_HOSTCACHE, "hostcache", "TCP hostcache"); #define HOSTCACHE_HASH(ip) \ (((ip)->s_addr ^ ((ip)->s_addr >> 7) ^ ((ip)->s_addr >> 17)) & \ V_tcp_hostcache.hashmask) /* XXX: What is the recommended hash to get good entropy for IPv6 addresses? */ #define HOSTCACHE_HASH6(ip6) \ (((ip6)->s6_addr32[0] ^ \ (ip6)->s6_addr32[1] ^ \ (ip6)->s6_addr32[2] ^ \ (ip6)->s6_addr32[3]) & \ V_tcp_hostcache.hashmask) #define THC_LOCK(lp) mtx_lock(lp) #define THC_UNLOCK(lp) mtx_unlock(lp) void tcp_hc_init(void) { u_int cache_limit; int i; /* * Initialize hostcache structures. */ V_tcp_hostcache.cache_count = 0; V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; V_tcp_hostcache.bucket_limit = TCP_HOSTCACHE_BUCKETLIMIT; V_tcp_hostcache.expire = TCP_HOSTCACHE_EXPIRE; V_tcp_hostcache.prune = TCP_HOSTCACHE_PRUNE; TUNABLE_INT_FETCH("net.inet.tcp.hostcache.hashsize", &V_tcp_hostcache.hashsize); if (!powerof2(V_tcp_hostcache.hashsize)) { printf("WARNING: hostcache hash size is not a power of 2.\n"); V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; /* default */ } V_tcp_hostcache.hashmask = V_tcp_hostcache.hashsize - 1; TUNABLE_INT_FETCH("net.inet.tcp.hostcache.bucketlimit", &V_tcp_hostcache.bucket_limit); cache_limit = V_tcp_hostcache.hashsize * V_tcp_hostcache.bucket_limit; V_tcp_hostcache.cache_limit = cache_limit; TUNABLE_INT_FETCH("net.inet.tcp.hostcache.cachelimit", &V_tcp_hostcache.cache_limit); if (V_tcp_hostcache.cache_limit > cache_limit) V_tcp_hostcache.cache_limit = cache_limit; /* * Allocate the hash table. */ V_tcp_hostcache.hashbase = (struct hc_head *) malloc(V_tcp_hostcache.hashsize * sizeof(struct hc_head), M_HOSTCACHE, M_WAITOK | M_ZERO); /* * Initialize the hash buckets. */ for (i = 0; i < V_tcp_hostcache.hashsize; i++) { TAILQ_INIT(&V_tcp_hostcache.hashbase[i].hch_bucket); V_tcp_hostcache.hashbase[i].hch_length = 0; mtx_init(&V_tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry", NULL, MTX_DEF); } /* * Allocate the hostcache entries. */ V_tcp_hostcache.zone = uma_zcreate("hostcache", sizeof(struct hc_metrics), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); uma_zone_set_max(V_tcp_hostcache.zone, V_tcp_hostcache.cache_limit); /* * Set up periodic cache cleanup. */ callout_init(&V_tcp_hc_callout, 1); callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, tcp_hc_purge, curvnet); } #ifdef VIMAGE void tcp_hc_destroy(void) { int i; callout_drain(&V_tcp_hc_callout); /* Purge all hc entries. */ tcp_hc_purge_internal(1); /* Free the uma zone and the allocated hash table. */ uma_zdestroy(V_tcp_hostcache.zone); for (i = 0; i < V_tcp_hostcache.hashsize; i++) mtx_destroy(&V_tcp_hostcache.hashbase[i].hch_mtx); free(V_tcp_hostcache.hashbase, M_HOSTCACHE); } #endif /* * Internal function: look up an entry in the hostcache or return NULL. * * If an entry has been returned, the caller becomes responsible for * unlocking the bucket row after he is done reading/modifying the entry. */ static struct hc_metrics * tcp_hc_lookup(struct in_conninfo *inc) { int hash; struct hc_head *hc_head; struct hc_metrics *hc_entry; if (!V_tcp_use_hostcache) return NULL; KASSERT(inc != NULL, ("tcp_hc_lookup with NULL in_conninfo pointer")); /* * Hash the foreign ip address. */ if (inc->inc_flags & INC_ISIPV6) hash = HOSTCACHE_HASH6(&inc->inc6_faddr); else hash = HOSTCACHE_HASH(&inc->inc_faddr); hc_head = &V_tcp_hostcache.hashbase[hash]; /* * Acquire lock for this bucket row; we release the lock if we don't * find an entry, otherwise the caller has to unlock after he is * done. */ THC_LOCK(&hc_head->hch_mtx); /* * Iterate through entries in bucket row looking for a match. */ TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) { if (inc->inc_flags & INC_ISIPV6) { /* XXX: check ip6_zoneid */ if (memcmp(&inc->inc6_faddr, &hc_entry->ip6, sizeof(inc->inc6_faddr)) == 0) return hc_entry; } else { if (memcmp(&inc->inc_faddr, &hc_entry->ip4, sizeof(inc->inc_faddr)) == 0) return hc_entry; } } /* * We were unsuccessful and didn't find anything. */ THC_UNLOCK(&hc_head->hch_mtx); return NULL; } /* * Internal function: insert an entry into the hostcache or return NULL if * unable to allocate a new one. * * If an entry has been returned, the caller becomes responsible for * unlocking the bucket row after he is done reading/modifying the entry. */ static struct hc_metrics * tcp_hc_insert(struct in_conninfo *inc) { int hash; struct hc_head *hc_head; struct hc_metrics *hc_entry; if (!V_tcp_use_hostcache) return NULL; KASSERT(inc != NULL, ("tcp_hc_insert with NULL in_conninfo pointer")); /* * Hash the foreign ip address. */ if (inc->inc_flags & INC_ISIPV6) hash = HOSTCACHE_HASH6(&inc->inc6_faddr); else hash = HOSTCACHE_HASH(&inc->inc_faddr); hc_head = &V_tcp_hostcache.hashbase[hash]; /* * Acquire lock for this bucket row; we release the lock if we don't * find an entry, otherwise the caller has to unlock after he is * done. */ THC_LOCK(&hc_head->hch_mtx); /* * If the bucket limit is reached, reuse the least-used element. */ if (hc_head->hch_length >= V_tcp_hostcache.bucket_limit || V_tcp_hostcache.cache_count >= V_tcp_hostcache.cache_limit) { hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead); /* * At first we were dropping the last element, just to * reacquire it in the next two lines again, which isn't very * efficient. Instead just reuse the least used element. * We may drop something that is still "in-use" but we can be * "lossy". * Just give up if this bucket row is empty and we don't have * anything to replace. */ if (hc_entry == NULL) { THC_UNLOCK(&hc_head->hch_mtx); return NULL; } TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q); V_tcp_hostcache.hashbase[hash].hch_length--; V_tcp_hostcache.cache_count--; TCPSTAT_INC(tcps_hc_bucketoverflow); #if 0 uma_zfree(V_tcp_hostcache.zone, hc_entry); #endif } else { /* * Allocate a new entry, or balk if not possible. */ hc_entry = uma_zalloc(V_tcp_hostcache.zone, M_NOWAIT); if (hc_entry == NULL) { THC_UNLOCK(&hc_head->hch_mtx); return NULL; } } /* * Initialize basic information of hostcache entry. */ bzero(hc_entry, sizeof(*hc_entry)); if (inc->inc_flags & INC_ISIPV6) { hc_entry->ip6 = inc->inc6_faddr; hc_entry->ip6_zoneid = inc->inc6_zoneid; } else hc_entry->ip4 = inc->inc_faddr; hc_entry->rmx_head = hc_head; hc_entry->rmx_expire = V_tcp_hostcache.expire; /* * Put it upfront. */ TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q); V_tcp_hostcache.hashbase[hash].hch_length++; V_tcp_hostcache.cache_count++; TCPSTAT_INC(tcps_hc_added); return hc_entry; } /* * External function: look up an entry in the hostcache and fill out the * supplied TCP metrics structure. Fills in NULL when no entry was found or * a value is not set. */ void tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite) { struct hc_metrics *hc_entry; - if (!V_tcp_use_hostcache) + if (!V_tcp_use_hostcache) { + bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); return; + } /* * Find the right bucket. */ hc_entry = tcp_hc_lookup(inc); /* * If we don't have an existing object. */ if (hc_entry == NULL) { bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); return; } hc_entry->rmx_hits++; hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu; hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh; hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt; hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar; hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd; hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe; hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe; /* * Unlock bucket row. */ THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); } /* * External function: look up an entry in the hostcache and return the * discovered path MTU. Returns 0 if no entry is found or value is not * set. */ uint32_t tcp_hc_getmtu(struct in_conninfo *inc) { struct hc_metrics *hc_entry; uint32_t mtu; if (!V_tcp_use_hostcache) return 0; hc_entry = tcp_hc_lookup(inc); if (hc_entry == NULL) { return 0; } hc_entry->rmx_hits++; hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ mtu = hc_entry->rmx_mtu; THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); return mtu; } /* * External function: update the MTU value of an entry in the hostcache. * Creates a new entry if none was found. */ void tcp_hc_updatemtu(struct in_conninfo *inc, uint32_t mtu) { struct hc_metrics *hc_entry; if (!V_tcp_use_hostcache) return; /* * Find the right bucket. */ hc_entry = tcp_hc_lookup(inc); /* * If we don't have an existing object, try to insert a new one. */ if (hc_entry == NULL) { hc_entry = tcp_hc_insert(inc); if (hc_entry == NULL) return; } hc_entry->rmx_updates++; hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ hc_entry->rmx_mtu = mtu; /* * Put it upfront so we find it faster next time. */ TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); /* * Unlock bucket row. */ THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); } /* * External function: update the TCP metrics of an entry in the hostcache. * Creates a new entry if none was found. */ void tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml) { struct hc_metrics *hc_entry; if (!V_tcp_use_hostcache) return; hc_entry = tcp_hc_lookup(inc); if (hc_entry == NULL) { hc_entry = tcp_hc_insert(inc); if (hc_entry == NULL) return; } hc_entry->rmx_updates++; hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ if (hcml->rmx_rtt != 0) { if (hc_entry->rmx_rtt == 0) hc_entry->rmx_rtt = hcml->rmx_rtt; else hc_entry->rmx_rtt = ((uint64_t)hc_entry->rmx_rtt + (uint64_t)hcml->rmx_rtt) / 2; TCPSTAT_INC(tcps_cachedrtt); } if (hcml->rmx_rttvar != 0) { if (hc_entry->rmx_rttvar == 0) hc_entry->rmx_rttvar = hcml->rmx_rttvar; else hc_entry->rmx_rttvar = ((uint64_t)hc_entry->rmx_rttvar + (uint64_t)hcml->rmx_rttvar) / 2; TCPSTAT_INC(tcps_cachedrttvar); } if (hcml->rmx_ssthresh != 0) { if (hc_entry->rmx_ssthresh == 0) hc_entry->rmx_ssthresh = hcml->rmx_ssthresh; else hc_entry->rmx_ssthresh = (hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2; TCPSTAT_INC(tcps_cachedssthresh); } if (hcml->rmx_cwnd != 0) { if (hc_entry->rmx_cwnd == 0) hc_entry->rmx_cwnd = hcml->rmx_cwnd; else hc_entry->rmx_cwnd = ((uint64_t)hc_entry->rmx_cwnd + (uint64_t)hcml->rmx_cwnd) / 2; /* TCPSTAT_INC(tcps_cachedcwnd); */ } if (hcml->rmx_sendpipe != 0) { if (hc_entry->rmx_sendpipe == 0) hc_entry->rmx_sendpipe = hcml->rmx_sendpipe; else hc_entry->rmx_sendpipe = ((uint64_t)hc_entry->rmx_sendpipe + (uint64_t)hcml->rmx_sendpipe) /2; /* TCPSTAT_INC(tcps_cachedsendpipe); */ } if (hcml->rmx_recvpipe != 0) { if (hc_entry->rmx_recvpipe == 0) hc_entry->rmx_recvpipe = hcml->rmx_recvpipe; else hc_entry->rmx_recvpipe = ((uint64_t)hc_entry->rmx_recvpipe + (uint64_t)hcml->rmx_recvpipe) /2; /* TCPSTAT_INC(tcps_cachedrecvpipe); */ } TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); } /* * Sysctl function: prints the list and values of all hostcache entries in * unsorted order. */ static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS) { const int linesize = 128; struct sbuf sb; int i, error; struct hc_metrics *hc_entry; char ip4buf[INET_ADDRSTRLEN]; #ifdef INET6 char ip6buf[INET6_ADDRSTRLEN]; #endif if (jailed_without_vnet(curthread->td_ucred) != 0) return (EPERM); sbuf_new(&sb, NULL, linesize * (V_tcp_hostcache.cache_count + 1), SBUF_INCLUDENUL); sbuf_printf(&sb, "\nIP address MTU SSTRESH RTT RTTVAR " " CWND SENDPIPE RECVPIPE HITS UPD EXP\n"); #define msec(u) (((u) + 500) / 1000) for (i = 0; i < V_tcp_hostcache.hashsize; i++) { THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); TAILQ_FOREACH(hc_entry, &V_tcp_hostcache.hashbase[i].hch_bucket, rmx_q) { sbuf_printf(&sb, "%-15s %5u %8u %6lums %6lums %8u %8u %8u %4lu " "%4lu %4i\n", hc_entry->ip4.s_addr ? inet_ntoa_r(hc_entry->ip4, ip4buf) : #ifdef INET6 ip6_sprintf(ip6buf, &hc_entry->ip6), #else "IPv6?", #endif hc_entry->rmx_mtu, hc_entry->rmx_ssthresh, msec((u_long)hc_entry->rmx_rtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), msec((u_long)hc_entry->rmx_rttvar * (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE))), hc_entry->rmx_cwnd, hc_entry->rmx_sendpipe, hc_entry->rmx_recvpipe, hc_entry->rmx_hits, hc_entry->rmx_updates, hc_entry->rmx_expire); } THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); } #undef msec error = sbuf_finish(&sb); if (error == 0) error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb)); sbuf_delete(&sb); return(error); } /* * Caller has to make sure the curvnet is set properly. */ static void tcp_hc_purge_internal(int all) { struct hc_metrics *hc_entry, *hc_next; int i; for (i = 0; i < V_tcp_hostcache.hashsize; i++) { THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); TAILQ_FOREACH_SAFE(hc_entry, &V_tcp_hostcache.hashbase[i].hch_bucket, rmx_q, hc_next) { if (all || hc_entry->rmx_expire <= 0) { TAILQ_REMOVE(&V_tcp_hostcache.hashbase[i].hch_bucket, hc_entry, rmx_q); uma_zfree(V_tcp_hostcache.zone, hc_entry); V_tcp_hostcache.hashbase[i].hch_length--; V_tcp_hostcache.cache_count--; } else hc_entry->rmx_expire -= V_tcp_hostcache.prune; } THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); } } /* * Expire and purge (old|all) entries in the tcp_hostcache. Runs * periodically from the callout. */ static void tcp_hc_purge(void *arg) { CURVNET_SET((struct vnet *) arg); int all = 0; if (V_tcp_hostcache.purgeall) { all = 1; V_tcp_hostcache.purgeall = 0; } tcp_hc_purge_internal(all); callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, tcp_hc_purge, arg); CURVNET_RESTORE(); } /* * Expire and purge all entries in hostcache immediately. */ static int sysctl_tcp_hc_purgenow(SYSCTL_HANDLER_ARGS) { int error, val; val = 0; error = sysctl_handle_int(oidp, &val, 0, req); if (error || !req->newptr) return (error); tcp_hc_purge_internal(1); callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, tcp_hc_purge, curvnet); return (0); }